Freeze-drying has been used in various applications for several years, such as in the food industry and pharmaceutical industry. Freeze-drying has also been used to prepare microorganisms such as bacteria for long term storage. In particular microorganism depositories such as the American Type Culture Collection often freeze-dry cultures for distribution since properly freeze-dried microorganisms remain viable at room temperature and can be transported without the need for solid carbon dioxide.
However, freeze-drying equipment is too expensive for day-to-day use by laboratory scientists who tend to keep microorganisms either as glycerol stocks at -80.degree. C. or in liquid nitrogen. Both forms of storage are relatively expensive and also carry the risk of loss of sample viability if the equipment fails. Nonetheless, a significant amount of storage space in -80.degree. C. freezers is given over to the storage of bacterial strains as glycerol stocks, for example to store bacterial colonies selected during cloning procedures. There is therefore a need to provide laboratory scientists with a means of storing large numbers of different microorganisms in an easily accessible format that does not require expensive freezer space.